﻿#define _CRT_SECURE_NO_WARNINGS
#include <stdio.h>
int average(int a,int b)
{
	return (b - a) / 2.0 + a;
}
int main()
{
	int a, b;
	scanf("%d%d", &a, &b);
	int avg = average(a,b);
	printf("%d", avg);
	return 0;
}